If you are in scope
A significant incident is identified. The clock starts here, not when you finish investigating.
Short. Can flag a suspected criminal act. This is the one people miss.
Severity, impact, indicators of compromise, contacts.
Cause, response taken, any cross-border effect.
The BSI can request them at any point between the deadlines.
The final report is due one month after the incident closes.
Certain incidents carry a duty to inform the recipients of your service.